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Emily & Yashaswini

We observed what the enzyme catalase does, so that should help us determine what an enzyme actually is.

 

The catalase broke up hydrogen peroxide into hydrogen and oxygen. The rate at which the enzyme did this to the hydrogen peroxide changed depending on several factors (we observed how temperature affects the rate). A cold catalase B-saturated filter took 15 seconds to float to the surface of 40ml of chilled hydrogen peroxide. A room temperature catalase B-saturated filter took only 9 seconds to float to the surface of 40ml of room-temperature hydrogen peroxide. A warm catalase B-saturated filter took 15 minutes to float to the surface of 40ml of warm hydrogen peroxide. We had hypothesized that since heat (usually?) stimulates more molecular movement, it would take less time for the bubbles that resulted in this reaction between hydrogen peroxide and catalase to push the filter to the surface in the “warm” experiment. We think now that enzymes perhaps have an “optimal” functioning temperature, and the warm temp. was just too high for the reaction to “happily” occur. The heat denatures enzymes, and then most of the enzymes become the wrong shape (we think…) to properly react with the hydrogen peroxide enzymes, so the reaction happens very slowly. The rate slows down significantly.

 

An enzyme is something that affects the rate at which reactions take place. We also hypothesize from our experiment and another experiment performed today with pH as the changing condition that extremities, ie hot vs cold, acidic vs basic, significantly slows an enzyme's ability to speed up a reaction.